We shall continue a variety of physical chemical studies on bacterial virus structure and assembly. These include: 1. Characterization of charge distribution, fibrous structure, and association of T4 tail fibers. 2. Seeking for myosin and actin-like proteins in T4 phage. 3. Determination of physical and association properties of gp63, and its role in acceleration of T4 tail fiber attachment. 4. Measure equilibrium and kinetics of T4 tail tube and sheath polymerization. 5. Measure T4 head-tail joining kinetics as a function of solution conditions. 6. Determine rate of DNA ejection from phage. 7. Study electrostatic forces in DNA condensation. 8. Study electrostatic effects on diffusion coefficients of DNA and other polyions. In these investigations, quasielastic light scattering and other hydrodynamic techniques will be primary tools.